/*****************************************************************************
* ac3_adec.h : ac3 decoder interface
*****************************************************************************
* Copyright (C) 1999, 2000 VideoLAN
* $Id: ac3_adec.h,v 1.5 2002/07/31 20:56:50 sam Exp $
*
* Authors: Michel Kaempf <maxx@via.ecp.fr>
* Renaud Dartus <reno@videolan.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*****************************************************************************/
/*****************************************************************************
* Prototypes
*****************************************************************************/
vlc_thread_t ac3dec_CreateThread( decoder_fifo_t * p_fifo );
/**** ac3 decoder API - public ac3 decoder structures */
typedef struct ac3dec_s ac3dec_t;
typedef struct ac3_sync_info_s {
int sample_rate; /* sample rate in Hz */
int frame_size; /* frame size in bytes */
int bit_rate; /* nominal bit rate in kbps */
} ac3_sync_info_t;
/**** ac3 decoder API - functions publically provided by the ac3 decoder ****/
int E_( ac3_init )(ac3dec_t * p_ac3dec);
int ac3_sync_frame (ac3dec_t * p_ac3dec, ac3_sync_info_t * p_sync_info);
int ac3_decode_frame (ac3dec_t * p_ac3dec, s16 * buffer);
/**** EVERYTHING AFTER THIS POINT IS PRIVATE ! DO NOT USE DIRECTLY ****/
/**** ac3 decoder internal structures ****/
/* The following structures are filled in by their corresponding parse_*
* functions. See http://www.atsc.org/Standards/A52/a_52.pdf for
* full details on each field. Indented fields are used to denote
* conditional fields.
*/
typedef struct syncinfo_s {
/* Sync word == 0x0B77 */
/* u16 syncword; */
/* crc for the first 5/8 of the sync block */
/* u16 crc1; */
/* Stream Sampling Rate (kHz) 0 = 48, 1 = 44.1, 2 = 32, 3 = reserved */
u16 fscod;
/* Frame size code */
u16 frmsizecod;
/* Information not in the AC-3 bitstream, but derived */
/* Frame size in 16 bit words */
u16 frame_size;
/* Bit rate in kilobits */
//u16 bit_rate;
} syncinfo_t;
typedef struct bsi_s {
/* Bit stream identification == 0x8 */
u16 bsid;
/* Bit stream mode */
u16 bsmod;
/* Audio coding mode */
u16 acmod;
/* If we're using the centre channel then */
/* centre mix level */
u16 cmixlev;
/* If we're using the surround channel then */
/* surround mix level */
u16 surmixlev;
/* If we're in 2/0 mode then */
/* Dolby surround mix level - NOT USED - */
u16 dsurmod;
/* Low frequency effects on */
u16 lfeon;
/* Dialogue Normalization level */
u16 dialnorm;
/* Compression exists */
u16 compre;
/* Compression level */
u16 compr;
/* Language code exists */
u16 langcode;
/* Language code */
u16 langcod;
/* Audio production info exists*/
u16 audprodie;
u16 mixlevel;
u16 roomtyp;
/* If we're in dual mono mode (acmod == 0) then extra stuff */
u16 dialnorm2;
u16 compr2e;
u16 compr2;
u16 langcod2e;
u16 langcod2;
u16 audprodi2e;
u16 mixlevel2;
u16 roomtyp2;
/* Copyright bit */
u16 copyrightb;
/* Original bit */
u16 origbs;
/* Timecode 1 exists */
u16 timecod1e;
/* Timecode 1 */
u16 timecod1;
/* Timecode 2 exists */
u16 timecod2e;
/* Timecode 2 */
u16 timecod2;
/* Additional bit stream info exists */
u16 addbsie;
/* Additional bit stream length - 1 (in bytes) */
u16 addbsil;
/* Additional bit stream information (max 64 bytes) */
u8 addbsi[64];
/* Information not in the AC-3 bitstream, but derived */
/* Number of channels (excluding LFE)
* Derived from acmod */
u16 nfchans;
} bsi_t;
/* more pain */
typedef struct audblk_s {
/* block switch bit indexed by channel num */
u16 blksw[5];
/* dither enable bit indexed by channel num */
u16 dithflag[5];
/* dynamic range gain exists */
u16 dynrnge;
/* dynamic range gain */
u16 dynrng;
/* if acmod==0 then */
/* dynamic range 2 gain exists */
u16 dynrng2e;
/* dynamic range 2 gain */
u16 dynrng2;
/* coupling strategy exists */
u16 cplstre;
/* coupling in use */
u16 cplinu;
/* channel coupled */
u16 chincpl[5];
/* if acmod==2 then */
/* Phase flags in use */
u16 phsflginu;
/* coupling begin frequency code */
u16 cplbegf;
/* coupling end frequency code */
u16 cplendf;
/* coupling band structure bits */
u16 cplbndstrc[18];
/* Do coupling co-ords exist for this channel? */
u16 cplcoe[5];
/* Master coupling co-ordinate */
u16 mstrcplco[5];
/* Per coupling band coupling co-ordinates */
u16 cplcoexp[5][18];
u16 cplcomant[5][18];
/* Phase flags for dual mono */
u16 phsflg[18];
/* Is there a rematrixing strategy */
u16 rematstr;
/* Rematrixing bits */
u16 rematflg[4];
/* Coupling exponent strategy */
u16 cplexpstr;
/* Exponent strategy for full bandwidth channels */
u16 chexpstr[5];
/* Exponent strategy for lfe channel */
u16 lfeexpstr;
/* Channel bandwidth for independent channels */
u16 chbwcod[5];
/* The absolute coupling exponent */
u16 cplabsexp;
/* Coupling channel exponents (D15 mode gives 18 * 12 /3 encoded exponents */
u16 cplexps[18 * 12 / 3];
/* Sanity checking constant */
u32 magic2;
/* fbw channel exponents */
u16 exps[5][252 / 3];
/* channel gain range */
u16 gainrng[5];
/* low frequency exponents */
u16 lfeexps[3];
/* Bit allocation info */
u16 baie;
/* Slow decay code */
u16 sdcycod;
/* Fast decay code */
u16 fdcycod;
/* Slow gain code */
u16 sgaincod;
/* dB per bit code */
u16 dbpbcod;
/* masking floor code */
u16 floorcod;
/* SNR offset info */
u16 snroffste;
/* coarse SNR offset */
u16 csnroffst;
/* coupling fine SNR offset */
u16 cplfsnroffst;
/* coupling fast gain code */
u16 cplfgaincod;
/* fbw fine SNR offset */
u16 fsnroffst[5];
/* fbw fast gain code */
u16 fgaincod[5];
/* lfe fine SNR offset */
u16 lfefsnroffst;
/* lfe fast gain code */
u16 lfefgaincod;
/* Coupling leak info */
u16 cplleake;
/* coupling fast leak initialization */
u16 cplfleak;
/* coupling slow leak initialization */
u16 cplsleak;
/* delta bit allocation info */
u16 deltbaie;
/* coupling delta bit allocation exists */
u16 cpldeltbae;
/* fbw delta bit allocation exists */
u16 deltbae[5];
/* number of cpl delta bit segments */
u16 cpldeltnseg;
/* coupling delta bit allocation offset */
u16 cpldeltoffst[8];
/* coupling delta bit allocation length */
u16 cpldeltlen[8];
/* coupling delta bit allocation length */
u16 cpldeltba[8];
/* number of delta bit segments */
u16 deltnseg[5];
/* fbw delta bit allocation offset */
u16 deltoffst[5][8];
/* fbw delta bit allocation length */
u16 deltlen[5][8];
/* fbw delta bit allocation length */
u16 deltba[5][8];
/* skip length exists */
u16 skiple;
/* skip length */
u16 skipl;
/* channel mantissas */
// u16 chmant[5][256];
/* coupling mantissas */
float cpl_flt[ 256 ];
// u16 cplmant[256];
/* coupling mantissas */
// u16 lfemant[7];
/* -- Information not in the bitstream, but derived thereof -- */
/* Number of coupling sub-bands */
u16 ncplsubnd;
/* Number of combined coupling sub-bands
* Derived from ncplsubnd and cplbndstrc */
u16 ncplbnd;
/* Number of exponent groups by channel
* Derived from strmant, endmant */
u16 nchgrps[5];
/* Number of coupling exponent groups
* Derived from cplbegf, cplendf, cplexpstr */
u16 ncplgrps;
/* End mantissa numbers of fbw channels */
u16 endmant[5];
/* Start and end mantissa numbers for the coupling channel */
u16 cplstrtmant;
u16 cplendmant;
/* Decoded exponent info */
u16 fbw_exp[5][256];
u16 cpl_exp[256];
u16 lfe_exp[7];
/* Bit allocation pointer results */
u16 fbw_bap[5][256];
/* FIXME?? figure out exactly how many entries there should be (253-37?) */
u16 cpl_bap[256];
u16 lfe_bap[7];
} audblk_t;
/* Everything you wanted to know about band structure */
/*
* The entire frequency domain is represented by 256 real
* floating point fourier coefficients. Only the lower 253
* coefficients are actually utilized however. We use arrays
* of 256 to be efficient in some cases.
*
* The 5 full bandwidth channels (fbw) can have their higher
* frequencies coupled together. These coupled channels then
* share their high frequency components.
*
* This coupling band is broken up into 18 sub-bands starting
* at mantissa number 37. Each sub-band is 12 bins wide.
*
* There are 50 bit allocation sub-bands which cover the entire
* frequency range. The sub-bands are of non-uniform width, and
* approximate a 1/6 octave scale.
*/
typedef struct bit_allocate_s
{
s16 psd[256];
s16 bndpsd[256];
s16 excite[256];
s16 mask[256];
s16 sdecay;
s16 fdecay;
s16 sgain;
s16 dbknee;
s16 floor;
} bit_allocate_t;
/* These store the persistent state of the packed mantissas */
typedef struct mantissa_s
{
float q_1[2];
float q_2[2];
float q_4[1];
s32 q_1_pointer;
s32 q_2_pointer;
s32 q_4_pointer;
u16 lfsr_state;
} mantissa_t;
/*****************************************************************************
* ac3dec_t : ac3 decoder thread descriptor
*****************************************************************************/
struct ac3dec_s
{
/*
* Decoder properties
*/
void * ac3_decoder_orig; /* pointer before memalign */
/*
* Thread properties
*/
vlc_thread_t thread_id; /* id for thread functions */
/*
* Input properties
*/
decoder_fifo_t * p_fifo; /* stores the PES stream data */
/* The bit stream structure handles the PES stream at the bit level */
bit_stream_t bit_stream;
int i_available;
unsigned int total_bits_read; /* temporary */
/*
* Decoder properties
*/
syncinfo_t syncinfo;
bsi_t bsi;
audblk_t audblk;
dm_par_t dm_par;
bit_allocate_t bit_allocate;
mantissa_t mantissa;
downmix_t * p_downmix;
/*
* Output properties
*/
aout_fifo_t * p_aout_fifo; /* stores the decompressed audio frames */
float * samples;
void * samples_orig; /* pointer before memalign */
imdct_t * p_imdct;
void * imdct_orig; /* pointer before memalign */
};